For example, as shown in Patent Document 1, there has been known a library device (also referred to as a data storage system or the like in some cases) which stores data cartridges within a plurality of cells. FIG. 6 is an example showing an external perspective view of a conventional library device.
As shown in FIG. 6, a library device 200 has magazines 260, drive devices 250, and an accessor device 240. The magazines 260 have a plurality of cells 280 for accommodating data cartridges in a horizontal attitude. The drive device 250 reads and writes data from and onto a recording medium within the data cartridge. The accessor device 240 transports data cartridges. The two magazines 260 are arranged in directions in which opening parts of the cells 280 oppose each other. The accessor device 240 has a picker mechanism (not shown in the figure) which take data cartridges in and out, and a swivel mechanism (not shown in the figure) for rotating the picker mechanism.
In general, an accessor device which transports data cartridges of a library device takes out a data cartridge from a drive device or a cell, and returns the data cartridge to the drive device. At this time, the accessor device pulls or pushes with a force that withstands the retentive force of the data cartridge or the resistance between the data cartridge and the drive device or the cell. Therefore, the accessor device requires a level of rigidity that withstands these forces. If the accessor device does not have this level of rigidity, it may not be able to pull out or return the data cartridge from or into the drive device and the cell in some cases.
If the height of the library device becomes high, the accessor device may collapse due to the above relationship of force in some cases, when the accessor device is operating to pull out or return the data cartridge. In order to perform these operations stably, there has been proposed a structure that is provided with a guide (refer to FIG. 3 of Patent Document 2). This type of structure has an extra structure added thereto compared to conventional structures. As a result, as a whole library device, this may cause the structure to become more complex and more large-scale.
In the accessor device of Patent Document 1, in order to realize stable operations of pulling out and returning a data cartridge without a guide, there is provided a structure in which the level of rigidity of the accessor device is made higher. This type of structure, compared to conventional structures, leads to a weight increase of the accessor device and limitation of materials to be used.